Matlab - Eliminar opción salir

function EjemploGUI

figure('MenuBar','none',...

    'CloseRequestFcn',@close_fcn);

uicontrol('style','push',...

    'String','Close',...

    'Callback',@close_fcn);

    function close_fcn(src,~)

        if strcmp(get(src,'type'),'uicontrol')

            delete(gcf);

        end

    end

end

% --- Executes on button press in exit.

function exit_Callback(hObject, eventdata, handles)

% hObject    handle to exit (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)